Biochips, on which biomolecules, such as DNAs or proteins, have been two-dimensionally arranged, are commonly used in studies on medical treatment and environmental conservation. In particular, protein chips, on which protein molecules (hereinafter, simply referred to as proteins) are two-dimensionally arranged on a chipboard, are being developed aiming at the applications including diagnosis, drug development, identity recognition, and biological system analysis.
A various kinds of probes (proteins) are arranged and immobilized on the chip board of a protein chip. Making samples such as blood contact with these proteins allows only specific targets (proteins) in the samples depending on the structures of the individual probes to binds to the probes. This means that the type of the target protein can be identified and the expression mechanism of proteins and the interaction among them can be also elucidated by converting any change in probe characteristic due to binding to the probe into an optical or electrical signal and reading it. Assuming that antibodies are used as probes, only specific antigens (antigens to specific viruses such as anthrax and smallpox) absorbed on the protein chip through the reaction with these antibodies and thereby, it can be determined whether the specific antigens harbor in the sample. Moreover, the quantity of antigens absorbed on the antibodies and the quantity of antigens removed from the sample are also capable of being determined.
However, as shown in FIG. 1, if a probe 1 has been arranged on a chip board 3 facing an arbitrary direction, the probe 1, which has not been correctly arranged, is not capable of absorbing a target 4.
Furthermore, a non-specific protein 5 may be caught within a gap formed around the probe 1 facing the arbitrary direction or the probe 1, which has been once immobilized on a chip board 3, may come away from the chip board 3 due to time-course changes and external factors.